By Mike LaBella
---- — HAVERHILL — Originally scheduled to be completed by late August, repairs to the Rocks Village Bridge will take a month longer than expected.
State transportation officials said the discovery of very small cracks in a key component of the span linking Haverhill and West Newbury required more work than expected.
The delay means vehicles which would normally use the bridge, including school buses, must continue using alternate routes until late September, when the bridge is expected to reopen. Students riding buses to nearby Whittier Regional High will face longer rides than usual during that first month of school.
The historic bridge, built in 1883 and rebuilt in 1914, is used by many residents in the Haverhill, West Newbury and Merrimac area, as well as those in southern New Hampshire communities such as Atkinson and Newton.
The state closed the bridge to traffic on June 18 of last year to begin work on the $13.1 million renovation. Drivers who used the 812-foot span have been forced be forced to find alternate routes.
Whittier Regional High had to change several of its bus routes during the last school year due to the bridge being closed. Whittier Superintendent William DeRosa said the change impacted six Whittier buses that formerly crossed the bridge in the morning and again in the afternoon.
DeRosa said his transportation coordinator devised a plan put into effect last fall, resulting in buses traveling Route 110 to Amesbury, with one or more of those buses traveling Interstate 95 to Georgetown. Whittier officials said until the bridge reopens, the buses will continue using those same alternate routes.
Michael Verseckes, a spokesman for the Massachusetts Department of Transportation, said the project involves a combination of replacing and repairing structural components because of the bridge’s historic significance.
“One of the components that was proposed to be rehabilitated was the ‘track chair,’’’ Verseckes said.
He said the track chair is a cast iron “ring” (similar to a lazy Susan) upon which sits a variety of equipment.
“Essentially, the primary purpose of the track chair is to support the swing span,” he said about the bridge’s movable center section.
Verseckes said an initial evaluation of the track chair showed it was in relatively good shape and, with rehabilitation, it was expected to meet or exceed the design life of the improved structure.
“Unfortunately, upon dismantling of the machinery, it was discovered that the track chair contained micro cracks that could not be readily identified during the initial visual inspections,” he said. “It was determined that a new track chair would have to be designed.”
He said MassDOT and the contractor worked to speed up the design and and the work hours on the project were expanded to a 12-hour shift, seven days a week. Verseckes said that despite those efforts, the unexpected additional work resulted in the reopening of the bridge being delayed by about one month.
Verseckes said various people affected by the project — including officials from Haverhill, West Newbury, Merrimac and Whittier Regional High — met last week to review the issue of the delay.
“Included in the discussion were two proposals – one that would allow the project to achieve the original opening date in late August, but which would require daily lane closures afterwards to complete additional work items, and a second that involved continuing the current schedule with the bridge closed with substantial completion of the project being pushed out to late September,” Verseckes said.
“We are moving forward with the latter option, as many believed that the inconvenience and uncertainly of the lane closures over an extended duration (possibly through November) after reopening was less desirable than simply extending the period of full closure by one month,” he said.
According to MassDOT, the Rocks Village Bridge contains the oldest movable span among all bridges presently under MassHighway control. It is located next to the Rocks Village National Register Historic District, on a site which has been utilized as a major Merrimack River crossing since the early 18th century. To date, only 44 movable bridges have been identified in MassHighway database. The Rocks Bridge, the oldest of them all, is still operated by hand.
It is one of the earliest riveted (as opposed to pin-connected) metal trusses yet identified in the MassHighway inventory, and the earliest known surviving work discovered to date of the Boston Bridge Works, a Massachusetts bridge building firm active from the 1870s through the 1930s.